A simple background with a stone texture is used.
When having Matinee work on my Sprite’s ‘Sprite Color’ Attribute, I change the Alpha from 1.0 to 0.0.
Now I play the game.
When the matinee executes, I see in the Actor details rollout the property does change, but the game does not reflect that, the Sprite is still visible.
The ‘Sprite Color’ property reads as FFFFFF00 which I would expect, and when I hit ‘Enter’, it updates and the Sprite is gone!
EDIT: also, it seems the same thing is happening with stuff like Movement tracks.